Peptide block, copolymers with

The lamellar structure of saccharide-peptide block copolymers presents many analogies with the structure of copolymers with a hydrophobic polyvinyl block and a hydrophobic polypeptide block and exhibits a similar behaviour as a function of the solvent concentration. When the solvent concentration increases the total thickness of a sheet and the thickness of the carbohydrate layer both increase while the thickness of the polypeptide layer remains nearly constant284. ... 

Linear polystyrene can be functionalized by various methods . The functional group capacity in these polymers diould not be too high otherwise, steric complications may arise. Poly(ethylene ycol) has been found to be most suitable for liquid-phase synthesis. This linear polyether and the block copolymers with functional groups at defined distances are chemically stable and soluble in a large number of solvents including water and can be precipitated selectively. Partially hydrolyzed poly(vinylpyrrolidone) and its copolymers with vinyl acetate were successfully applied in peptide synthesis. Poly(acrylic acid), poly(vinyl alcdiol), and poly-(ethylenimine) are less suitable for the sequential type synthesis because of the... 

This review discusses the sohd-state structure, organization and properties of peptide-synthetic hybrid block copolymers. Hybrid block copolymers composed of a synthetic block and a peptide segment are an interesting class of materials, both from a structural and a functional point of view [14-16]. Peptide sequences can adopt ordered conformations such as a-hehces or /J-strands. In the former case, this leads to block copolymers with rod-coil character. Peptide sequences with a /1-strand conformation can un-... 

Linear polypeptide block copolymers, block copolymers with pendent sugar or peptide grafts, and modified linear or dendritic homopolymers have been used to produce vesicles based on hydrophobic interactions and packing issues. Usually, the peptides or sugars make the minority hydrophilic part of the copolymers and are thus incorporated in the corona and not in the membrane of the vesicles. For the inverse case, the hydrophobic peptides in the membrane are often too short to adopt a stable secondary structure. 

For all copolymers studied (copolymers containing between 18 % and 83 % of polypeptide] the liquid crystalline structures are always lamellar and are very similar to the structure of saccharide-peptide block copolymers. In the lamellar structure of copolymers with a polyvinyl block and a hydrophobic polypeptide block, each sheet of thickness d results from the superposition of two layers one of thickness d/ formed by the polyvinyl chains in a more or less random coil conformation, the other of thickness dg formed by the polypeptide chains, in an a helix conformation, arranged in an hexagonal array, and generally folded ( 7, 8]. ... 

The transition from hybrid block copolymers with a homopeptide block toward those with sequence-defined peptide segments enriches the self-assembly behavior strongly. Ayers et smdied water-soluble block copolymers composed of a PEO block and a peptide block with comb architecture, which was obtained by the controlled polymerization of oligopeptide... 

A large portion of the research up to this point has been carried out on materials composed of a synthetic block and a peptide block. These peptide-polymer conjugates combine the advantages of synthetic polymers (such as solubility, processability, and rubber elasticity) with those of polypeptides or protein-like polymers (such as secondary structure, functionality, and biocompatibihty). While synthetic polymers generally present a coil structure, peptide sequences can adopt ordered conformations such as a-helices or jS-strands (Figure 20.1). The former case produces block copolymers with a rod-coil character such rod-coil block copolymers have generated unconventional nanoscale structures not observed for purely amorphous block copolymers. Copolymers containing peptide sequences with a jS-strand... 

Kang et al. studied the influence of stereochemistry of the peptide block on the properties of PEG-h-poly(alanine-co-phenylalanine) (PEG-l PAF and PEG-d PAE) [65]. The block copolymers with similar molecular weights but different stereochemistry were similar in their phase diagrams regarding the sol-to-gel transition of the aqueous solution and temperature-sensitive changes in their self-assemblies. 

Fig. 6 Glycosylated peptide block copolymers. Reprinted from [107] with permission. Copyright 2011, American Chemical Society...

Tsutsumiuchi K, Aoi K, Okada M (1997) Synthesis of polyoxazoline-(glyco)peptide block copolymers by ring-opening polymerization of (sugar-substituted) alpha-amino acid N-carboxyanhydrides with polyoxazoline macroinitiators. Macromolecules 30(14) 4013-4017... 

Ma J, Feng P, Ye C, Wang Y, Fan Y (2001) An improved interfacial coacervation technique to fabricate biodegradable nanocapsules of an aqueous peptide solution from polylactide and its block copolymers with poly (ethylene glycol). Colloid Polym Sci 279(4) 387-392... 

Recently, unique vesicle-forming (spherical bUayers that offer a hydrophilic reservoir, suitable for incorporation of water-soluble molecules, as well as hydrophobic wall that protects the loaded molecules from the external solution) setf-assembUng peptide-based amphiphilic block copolymers that mimic biological membranes have attracted great interest as polymersomes or functional polymersomes due to their new and promising applications in dmg delivery and artificial cells [ 122]. However, in all the cases the block copolymers formed are chemically dispersed and are often contaminated with homopolymer. 

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